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A070760
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Numbers n such that n*rev(n) is a square different from n^2, where rev=A004086, decimal reversal.
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1
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100, 144, 169, 200, 288, 300, 400, 441, 500, 528, 600, 700, 768, 800, 825, 867, 882, 900, 961, 1089, 1100, 1584, 2178, 2200, 3300, 4400, 4851, 5500, 6600, 7700, 8712, 8800, 9801, 9900, 10000, 10100, 10404, 10609, 10989
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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LINKS
| Reinhard Zumkeller, Table of n, a(n) for n = 1..1000
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EXAMPLE
| a(2)=144: rev(144)=441, 144*441=(12^2)*(21^2)=(12*21)^2 and 144<>12*21=252.
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MATHEMATICA
| Select[ Range[11000], (k = Sqrt[ # * FromDigits @ Reverse @ IntegerDigits[#]]; IntegerQ[k] && k != #) &] (* From Jean-François Alcover, Nov 30 2011 *)
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PROG
| (Haskell)
a070760 n = a070760_list !! (n-1)
a070760_list = filter q [1..] where
q n = a010052 x == 1 && x /= n^2 where
x = n * a004086 n
-- Reinhard Zumkeller, Apr 29 2011
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CROSSREFS
| Cf. A061205, A010052, A002113.
Sequence in context: A045211 A108551 A096598 * A161902 A153673 A004262
Adjacent sequences: A070757 A070758 A070759 * A070761 A070762 A070763
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KEYWORD
| nonn,nice,base
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AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), May 15 2002
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